Analytical approach for optimization design of MEMS based microneedles in drug delivery system

Abstract

Microneedles have been recently given much attention as a novel way for transdermal drug delivery. In this paper, the mechanics of microneedle insertion into soft tissue and also the changes in the forces and moments of the microneedle is to be presented. A non-linear displacement of the microneedle insertion into the soft tissue is expressed as a quadratic polynomial function and solved using Galerkin technique. The geometrical behavior of the microneedle tip is to be considered in the analytical model. The microneedle insertion is classified into two phases namely, pre-puncture and post-puncture. An analytical model of microneedle stiffness coefficient and effect of interfacial contact force in frictionless condition are derived using Love’s thin rod theory. The interfacial contact stresses at the interface between the microneedle and soft tissue are obtained from the contact forces using the Hertzian theory. Statistical analysis based on the analytical model was done for studying various effects of process variables on the dependent variables. The statistical analysis was done by Analysis of variance (ANOVA). The graphical analysis of the analytical model are presented using MATLAB. The analytical model helps to improve the microneedle design by minimizing the pain of insertion and increasing the mechanical strength.